BCMA-Directed CAR T-Cell Therapy in Patients with Relapsed/Refractory Multiple Myeloma and Renal Impairment

The pivotal clinical trials, CARTITUDE-1 and KarMMa-3, showed promising response rates in relapsed and refractory multiple myeloma (RRMM) with use of BCMA-directed CAR T-cell therapy; however, a major challenge is determining suitability in patients who do not meet trial inclusion criteria due to suboptimal organ function. In this multicenter retrospective study, we evaluated the safety and efficacy of BCMA CAR-T therapy in patients with RRMM and renal impairment (RI), defined as creatinine clearance (CrCL) of less than 45 mL/min. We evaluated 223 patients treated with idecabtagene vicleucel (ide-cel) or ciltacabtagene autoleucel (cilta-cel) between May 2021 and April 2024. Outcomes were compared between baseline RI (11.2%) and normal renal function (nRF) cohorts. Response rates were similar at 1 month (p = 0.09), 3 months (p > 0.9), and 6 months (p = 0.8). Progression-free survival (PFS) was 21.9 months in the RI group compared to 15 months in the nRF group (p = 0.32), while overall survival (OS) was 27.9 months for patients with RI versus not reached for patients with nRF (p = 0.87). Patients with RI had higher rates of immune effector cell-associated neurotoxicity syndrome (ICANS) (60% vs. 19%, p = 0.04) and infections (44% vs. 20%, p = 0.008). We found that BCMA CAR-T demonstrated comparable efficacy in RRMM patients with baseline RI, although these patients exhibited increased rates of neurotoxicity and infections.